What is the best powered thunderbolt dock for Mac Mini M4?

There are several docks available. Looks like you want to connect several drives so assuming you do not want to use all your TB ports on your Mac then a dock like this may work:

https://www.amazon.com/OWC-Thunderbolt-Dock-Compatible-Equipped/dp/B097TVLB4F?th=1

However, the only drawback is that the connection to your Mac is on the front and I would prefer a back connection. The newer TB5 docs are on the back like this one:

https://www.amazon.com/Cable-Matters-Thunderbolt-Docking-Station/dp/B0CM4VGTS8/ref=sr_1_1?crid=2J079XP0ANN7A&dib=eyJ2IjoiMSJ9.wtckoHo0k5yBu_M72gPXd7t_126z3ra4wbixb6p502fTIgcwLGDxPeFIRezlxqLswmc5RovY4F0bo3WJBCpivWU04flwJYq1kgBzxE3egJtVNQOElPCg2m4uPcEDdJd-slIADjUwQTmgb8JgXJ0nN7Jp-yoIvh7wcTk9ohdDHOFXXkpStdzlPDhD6nQOai1r2l3DSsevrQV5BwLXAJ0Pi7VxUds588hIYqlo6fSi1sOb58IzWFzyEgqqTVCsLxGmViilAlaK_uAvSXpE4v44MGft0StUwmsKVZOmnv4Xozw.uS3jr4GBZtUN1K5_GIRBkSmD-9VcdkZDtH7NcO9pnSU&dib_tag=se&keywords=cable+matters+thunderbolt+4+dock&qid=1745181322&s=electronics&sprefix=cable+amtters+thunderbolt+4+dock%2Celectronics%2C95&sr=1-1

FWIW, I have had a number of docks from OWC, including the miniStack STX that I'm currently using with my 2023 M2 Pro Mac mini. Although this is not something you were looking for, I can attest to the excellent quality and support from OWC and would highly recommend them as a source for docks for your M4 mini. They also have an excellent return policy. I suggest that you give them a call and have one of their sales specialists guide you through what they have to offer to see which one(s) can meet your goals for M4 dock.

I use the OWC TB5 dock (with my Mac Mini M4 pro) but it may not have enough USB ports for your use. The dock works fine.